1. Field of the Invention
The present invention relates to a light receiving and emitting probe and to a light receiving and emitting probe apparatus that illuminate extremely small regions on the surface of a sample and receives light from such extremely small regions.
2. Prior Art
In the past, the development of light emitting materials has progressed very rapidly, and a new technical field known as opto-electronics, which uses light and electrons, has been proposed. Various technical developments such as light emitting diodes, laser diodes, plasma, fluorescence, liquid crystals, electroluminescence and optical ICs, etc. have been accomplished in this field.
However, such optical techniques deal mainly with regions in which the size of the visual field is on the naked-eye level or optical-microscopic level, and they do not deal with nano-regions, in which there has been rapid development in recent years. Techniques for illuminating very small regions by way of optical fibers have been developed. However, since optical fibers cannot be reduced to nano-size, free control of illumination and extinction in nano-regions is not possible.
Meanwhile, atomic force microscopes (AFM) and scanning type tunnel microscopes (STM) have been developed, and techniques for imaging sample surfaces at the atomic level or controlling the movement of atoms on sample surfaces are under development. In connection with the development of such techniques, there is a need for optical techniques that allow efficient pinpoint illumination and extinction in nano-size regions.
In recent years, optical fiber techniques that propagate evanescent waves in optical fibers have been proposed. In such optical fiber techniques, extremely small regions are illuminated by way of utilizing light that oozes out from the tip end of an optical fiber. However, such techniques suffer from numerous problems in terms of, among others, manufacture of the tip end opening portions and handling of the fibers. Furthermore, since the light intensity of evanescent waves attenuates exponentially, the light utilization efficiency is not good. In other words, inversely proportionate to the size of the demand for nano-region light emitting technique, there has been no nano-region light emitting technique so far that can be effectively utilized.
Accordingly, it is an object of the present invention to provide a light receiving and emitting probe and a light receiving and emitting probe apparatus with a nano-region illumination technique that allows pinpoint illumination and pinpoint extinction in nano-regions on the surfaces of substances, thus effectively utilizing such nano-regions.
It is another object of the present invention to provide a light receiving technique that makes it possible to receive light emitted from extremely small regions, nano-regions, on the surfaces of samples.
In other words, the present invention is for a light receiving and emitting probe and a light receiving and emitting probe apparatus in which a light receiving and emitting body is formed on the side surface of a conductive nanotube probe needle fastened to a holder and in which a light receiving and emitting body is formed on the side surface of the protruding portion of an AFM cantilever, thus receiving and emitting light by this light receiving and emitting body.
More specifically, the above objects are accomplished by a unique structure of the present invention for a light receiving and emitting probe that comprises:
a conductive nanotube probe needle with its base end portion fastened to a holder and its tip end portion protruded,
a light receiving and emitting body which is provided on the circumferential surface of the conductive nanotube probe needle, and
a conductive nanotube lead wire fastened to the light receiving and emitting body.
Moreover, the above light receiving and emitting probe can be further provided with a means that applies an electric voltage between both ends of the conductive nanotube lead wire and the conductive nanotube probe needle, so that light can be received and emitted by the light receiving and emitting body.
In the light receiving and emitting probe of the present invention, an AFM cantilever in which a protruding portion used as the holder is formed on a cantilever portion thereof is employed, two electrode films are formed on the cantilever portion, one end of the conductive nanotube lead wire is connected to one of the electrode films, and the conductive nanotube probe needle is connected to another of the electrode films, so that an electric voltage is applied between the electrode films.
Furthermore, in the present invention, an AFM cantilever in which a protruding portion used as the holder is formed on a cantilever portion thereof is employed, two electrode films are formed on the cantilever portion, one end of the conductive nanotube lead wire is connected to one of the electrode films, the conductive nanotube probe needle and the other of the electrode films are connected by means of another conductive nanotube lead wire, so that an electric voltage is applied between the electrode films.
In addition, the above objects are accomplished by another unique structure of the present invention for a light receiving and emitting probe, in which an AFM cantilever that has a protruding portion formed on a cantilever portion thereof is employed, two electrode films are formed on the cantilever portion, and a light receiving and emitting body is formed near a tip end of the protruding portion, so that both ends of the light receiving and emitting body and the two electrode films are made electrically continuous, and the light receiving and emitting body is caused to receive and emit light by causing an electric current to pass between the two electrode films.
Furthermore, the above objects are accomplished by a unique structure of the present invention for a light receiving and emitting probe apparatus that comprises:
the light receiving and emitting probe described above,
a scanning mechanism that operates the light receiving and emitting probe to scan over a sample, and
a control circuit that causes light to be received and emitted by a light receiving and emitting body of the light receiving and emitting probe.